Mine is effed up right now. For some reason one of the tubes blew and when I removed it, the little port that the tube plugs into has a black spot like two of the pins arced. I'm not sure what the hell happened but now even after replacing both tubes, only one tube glows when I turn it on. I don't have the cash to get it repaired right now but hopefully next month I can get it taken care of.
Probably blew the screen resistor when the arc happened. Be happy; a screen resistor is a lot cheaper to replace than a transformer. It's an easy fix for a tech.
Super nice amp. Why in the world would you pull a tube while it was on?